Food mixer electric motor assembly



March 7, 1950 s. Masm FOOD MIXER ELECTRIC MOTOR ASSEMBLY 2. Sheets-Sheet1 Filed June 3, 1947 IIIIIIIIIIIIIIIM'WIIIII 4 urea. fiepfwn March 7,.1950 s. MISIC 2,499,923

FOOD MIXER ELECTRIC MOTOR ASSEMBLY Filed June 3, 1947 2 Sheets-Sheet 2IN V EN TQR. 1323072672 M13503,

Patented Mar. 7, 1950 FOOD MIXER ELECTRIC MOTOR ASSEMBLY Stephen Misic,Berwyn, Ill., assignor to Franklin Appliance Company, Chicago, 11]., acorporation of Illinois Application June 3, 1947, Serial No. 752,232

This invention is concerned with improvements in a food mixer.

It is an object of the invention to provide a food mixer of the portablehand-manipulated type which is simple, compact, light in weight, yet ofrugged construction, and which will efficiently mix various kinds ofmaterials having varying viscosities.

A more specific object of the invention is to provide a food mixercomprising a light, compact driving motor having secured, at oppositeends and axially of the driving shaft, bearing supporting structures,one of which provides for supporting a fan at that end of the motor andthe other of which provides a compartment at the opposite end of themotor accommodating driving gears for rotating in opposite directionsconcentrically mounted beater shafts, the compartment being closed by aplate on which the gears and the connecting drive mechanism for thebeater shafts are supported.

A further object of the invention is to provide a food mixer of the typedescribed inwhich a driving motor, a cooling fan and gear mechanism fordriving concentrically arranged beater shafts are operatively associatedby supporting structures which are adapted to be securedtoeach other inalignment and which comprise separable elements provided with closelyinterfitting portions whereby the motor and the supporting structuresmay be readily assembled in properly aligned relation by moving theseparable elements axially into position and then interengaging the samewith a snap action.

It is another object of the invention to provid ina food mixerconstruction a driving motor anda driving mechanism for concentricallyar ranged beater shafts which are arranged so that 6 Claims. (01.172-36) vlbrationless operation of the beater shafts is obtained.

It is another object of the invention to provide a food mixer mechanismfor driving concentrically arranged beater shafts wherein the motorshaft andthe beater shafts are supported in axial alignment with the endof the inner beater shaft journaled in the end of the motor shaft tothereby eliminate chattering in the beater shafts.

It is another object of the invention. to provide in a food mixer acasing having a central section and separable end sections wherein thecentral section of the casing is adapted to receive a driving motorsupporting unit having incorporated in one end a cooling fan and in theother end a gear driving mechanism for concentrically arranged beatershafts and wherein the end sections of the casing may be removed toprovide access to the respective ends of the motor supporting unit.

It is another object of the invention to provide in a portable mixer aseparable handle member which may be readily attached to or detachedfrom the mixer casing by a simple latch mechanism.

These and other objects and advantages will be apparent from adescription of the preferred form of the food mixer which is shown, byway of illustration, in the accompanying drawings, wherein:

Fig. l is a side elevation of a food mixer embodying the principles ofthe invention;

Fig. 2 is a longitudinal section through the mixer casing, to anenlarged scale;

Fig. 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a section on the line 4-4 of Fig. 2;

Fig. 5 is a section on the line 5-5 of Fig. 2;

Fig. 6 is a section on the line 66 of Fig. 2; and

Fig. 71s a section on the line 1-1 of Fig. 2 Referring to the drawings,the mixer construe tion comprises a casing or housing 10 which is.

adapted to enclose a driving motor, speed control mechanism for themotor and gear mechanism for connecting the motor shaft in drivingrela-, tion to the inner ends of short concentric shafts,-

the beater shafts being adapted to be connected to theouter ends of theshort connecting shafts for rotation thereby when the motoris operated.v The casing ID includes a centralsection ormain portion II and endsections. l2 and.l3. The central section II houses the motor, a cool-'ing fan and a gear mechanism for driving the beater shafting, all ofwhich are initially assembiedas a single unit and. inserted in thecasing. The top end section I2 supports the speed con trol mechanism andencloses'thetop end of the motor unit. The bottom end section l3encloses the lower end of the motor unit and is provided with a centralaperture l4 through which the shaft structure I 5 extends for connectingthe motor sh ft indriving rela ion with the eater shafts. The casingsections ll, l2 and I3 are secured to each other by screws or similarsecuring means. The motor unit is secured within the casing ill by anyconventional fastening means.

The mixer mechanism is adapted to rotate, in opposite directions,concentrically arranged inner and outer beater shafts l6 and I1,respectively. The inner beater shaft I6 is provided at its lower endwith a mixing screw element 18 and the outer beater shaft I1 is providedwith a cooperating mixing element l9. The beater shafts l and I! areadaptedtobe detachably secured on the connecting-shaft structure l5which extends downwardly through the aperture I4 in the casing sectioni3. The beater construction and the mechanism for detachably securingthe same to the connecting shaft structure are more fully described inapplicants copending application, Serial No. 729,113, filed February17,1947.

The mixer is adapted to be supported by a handle 2|] which is detachablyconnected to the casing iii and which is proportioned and shaped toprovide for comfortably holding the mixer in any desired position withthe least amount of fatigue. The upper end ,2! of handle .20 conforms tothe contour of the casing l0 andis provided with a recess .or bore 22whichis adapted to receive a securing pin 23. The pin v23 is fixed toand extends outwardly of section II of the casing. The pin 23 isprovided with a transverse groove 24 which accommodates a transverselatching pin'25 journaled in thehandle end 2h: .The latching pin .25 isoperable by a handle member 25 and is provided with a transverse groove.21. When the handle is positioned with the securing pin 23 seated inthe recess22 and the latching pin in normal latching position, thehandle is securely latched to the .casing byengagement of the latchingpin 25 in the groove 24 in the securing pin 23. The handle 23 may beremoved by rotating the latching pin .-.25 180 degrees to bring thegroove 21 into position to accommodate the securing pin ,23 and permitwithdrawal of securing pin '23 from the recess22. With 'Themotor unitwhich is housed in the central section II of the casing Ill comprisesthe motor body or laminated stator core structure 28, spacing bracketmembers 29 and 30 extending inoppositej directions therefromand bearingbracket members 31 and 32, respectively. The bracket members 29, 39, 3|and 32 are preferably castings oi'light metal, such as aluminum.

' The bracket member 29 consists of-a plate-like topportion 33V anddepending legs or'feet'34'. The bracket] 30 consists of a plate-'likejbottom portion 3 5 and 'upstanding'legs orjieet 36. The legs34, and' 3'6of'bra'ckets 291and 30, respectively, are UF-shaped and provided withlaterally extending bright "portions which are aperturedfltoreceivebolts or rivets '31 by. means vof which T the' lbrackets ly" secureditothe motor laminations' 28. laminated 's'tructure"'28 "*and .the spacingbra kets: 29'and sci-are arranged to accommodate the motor armaturesa.having. shaft 39 .and com--. mam-14o: J 'jIi'Ih' upper end of the motorshaft39 is'.'jourdated in a self-lubricating hearing which isiiiountedin the top or Iend'plate portion 42 of sup porltingbracket'm'ember' 3|. Depending legs. .43 onhtacket'mjember 31'crisaeeztheqvip"9 39339;

the spacing bracket 29 and are secured thereto by screws 44. The topplate 33 of spacing bracket 29 is provided with shelf or ledge portionswhich cooperate with similar shelf or ledge portions 46 on the engagingportions of legs 43 of bracket 31 to accommodate the brush holdersupporting plate 41.

Plate 41 is provided with a central aperture 49 in which the commutator49 rotates. The aperture 43 is larger in diameter than the commutator 40and provides a path for air circulation. Brush holders 49 are secured onthe lower face of plate 47 for receiving the brushes 53 which are heldin engagement with the commutator 43 by spring members 5i secured on theplate 41. The plate 41 is held in position between the bracket members29 and 3| and a close interlocking fit is provided so that whenpositioned in proper alignment and moved axially toward bracket 2 9,plate 41 will snap into position on the ledge portions 45 and whenbracket 35 is positioned thereover and moved toward bracket 29 it willsnap into properly seated position. Portionsof plate 47 extend radiallybetween the legs 34 of the bracket 29 and legs 43 of bracket 36 so thatplate 47 will not rotate out of its initial set position and brushes 59are maintained in proper predetermined circumferential position relativeto the commutator 49.

The top plateportion 42 of bracket 3i is spaced asufiicient distancefrom the top plate portion 33 of the bracket 29 to accommodate amultiblade fan 52 which is keyed to the motor shaft 39 and rotatestherewith to circulate air within the casing iii. The casing i0 isprovided with a series'of air holes 59 in the lower end adjacent the endof the armature 38 and another series of air holes 54 in the upper endadjacent the peripheryof the fan 52. The fan 52 draws air through holes53, circulates it around the armature'38 and commutator 46, through theaperture 48 in plate 4! and out the holes 54 and prevents overheating ofthe motor.

The bottom plate portions 35 of spacing bracket 39 are provided withinner shoulder forming portions 55 for receiving in close fittinginterengaging relation projecting top plate portion 53 of the bearingbracket 32. The bracket 32 is-secured to the bracket 39b means of screws51. Thebracket 32 supports a self-lubricating bearing 58 in a bushing59. The lower end of the motor shaft 39 is journaled in the bearing 58and extends a short distance therein. A floating shaft'section '69 isprovided with one end extendi inginto the bearing 53 and into abuttingrelation with the lower end of the motor shaft 39.. I nterengagingportions on the abutting ends of the shaftsseparably connect the shaftssothat shaft-section Ellis rotatably driven by "the motor shaft 39 andforms an end extension thereon-.- The otherend of shaftsection'fiiiproj-ectsintoa outwardly opening"gear compartment 166- in thebracketi3z" and a drivin-g pinion-32 is secured in fixedjrelationthereon? A" plate member"thisadapted to' close" the bottom end ofcompartment3i. The "bracket 32 {is "provided "witnperipheral' recess"forming s oulder pDItlOl'lSBQ: having a'c'lose interloci'ringfitwithperiphera'l portions of platetiiS:

"Plate 53' "is provided with-a d'ownwardly"ex= tending" central hubhaving" secured therein atwo:paftfselflubricating"bearing 35 in whicharev journaled'i'relatively' short"se'ction's"f or con centric outer andinner shafting 3'! and 58,.r'ei 'iviil'fiih. IQfldd liiilfi???tattle-31%;. 1 19 .13.

are provided at the lower end of bearing 66. The shaft sections 6! and68 which are separated from each other by bearing ll extend downwardlyand constitute part of the beater shaft connecting structure l5.

The outer shaft section 61 has secured on its upper end a fiber gear 12.The inner shaft section 68 projects upwardly beyond the end of outershaft section 67 and has secured on its upper end a metal gear 73. Theshaft section 68 has a reduced end portion 14 which is journaled in abearing 15 in an axial recess formed in the lower end of floating shaft60. By means of this construction the rotating shafts are held insubstantially perfect alignment and there is no chattering in the beatershafts.

A shaft 76 is journaled at one end in the bearing 11 in the wall ofcompartment 6| and at the other end in the bearing 78 in the cover plate63. A fiber gear 19 is secured on shaft 16 and meshes with pinion 62 onthe floating shaft 60, being driven thereby. A relative wide pinion 86is secured on the shaft 16 and meshes with gear 12 on the connectingshaft section 61 to rotate the outer beater shaft. The pinion 80 alsomeshes with a fiber gear 8| which is mounted on a stub shaft 82projecting from the plate 63. The gear 8! meshes with the gear 13 on theconnecting shaft section 68 to rotate the inner beater in the oppositeor reverse direction to the direction of rotation of the outer beater.

The cover plate 63 is secured to the bracket member 32 by means ofscrews 83 or the like and completely closes the compartment 6|. Thecompartment 6| may be filled with grease or other lubricating materialprior to being closed by the plate 63.

The upper end section [2 of the casing I supports a speed control devicefor the motor which preferably comprises a multi-point switch 84 forcontrolling the motor field winding and thus varying the speed of themotor. An operating knob or handle member 85 is provided on the end ofthe casing section l2 and a cooperating dial or other markings may beprovided to indicate the position of the same for various motor speeds.A current supply cord 86 of appropriate length extends through anaperture 81 in the casing section I2 and provides for supplying currentto operate the motor.

The arrangement of the motor body, the spacing brackets and the bearingsupporting brackets so that they may be easily and quickly separatedfrom each other not only adapts the device to rapid and economicalmanufacture but also greatly reduces the cost of maintenance since allthe parts are readily accessible for examination, repair andreplacement. The driving gear mechanism may be entirely removed withoutdisassembly of the motor by removing casing section 13 and separatingbracket 32 from the spacing bracket 30.

While specific materials and details of construction have been referredto in describing the illustrated form of the invention, it will beunderstood that other materials and other details of construction withinthe spirit of the invention may be resorted to.

I claim:

1. In a food mixer, a motor stator core, spacer brackets connected tosaid stator core, motor shaft bearing holders connected to said spacerbrackets, one of said bearing holders having a compartment, a motorshaft extension projecting into said compartment and being separablefrom the motor shaft, a cover plate for said conipartment, concentricbeater shaft driving members journaled in said cover plate with theiraxes in alignment with the motor shaft, and gear drive mechanism forrotating said beater shaft driving members from the motor shaft, the endof one of said beater shaft driving members being journaled in the endof said motor shaft extension.

2. In a food mixer, a motor stator core, brackets extending fromopposite sides of said stator core and supporting motor shaft bearings,one of said brackets having a compartment adjacent the shaft bearing, acover for said compartment, concentric beater shaft connecting membersjournaled in said cover and extending into said compartment, arelatively short floating shaft section in said shaft bearing having oneend extending into said compartment, a bearing in said end of saidfloating shaft for receiving the end of the inner one of said concentricbeater shaft connecting members and gear members connecting saidfloating shaft section and said beater shaft connecting members indriving relation, said floating shaft being provided with separablemeans for connecting the same to the motor shaft.

3. A food mixer comprising a motor stator core, spacer members securedto each side of said motor stator core and motor shaft bearingsupporting members secured to said spacer members, one of saidsupporting members having a gear drive receiving compartment and a coverplate member for said compartment, said spacer members and said bearingsupporting members having close interfitting portions on their engagingsides whereby when said interfitting portions are aligned and saidbearing supporting members are moved axially relative to said spacermembers they will engage in close frictionally interlocked relation witha snap action.

4. A food mixer comprising a motor stator core, separable bracketmembers attached to opposite sides of said motor stator core, motorshaft bearing members in said bracket members, a gear compartment in oneof said bracket members at one end of said motor shaft, a bearing insaid compartment in alignment with the motor shaft bearing members,relatively short concentric drive members for beater shafts journaled insaid bearing and extending into said compartment, driving gears in saidcompartment connecting said motor shaft to said drive members and a fansupported on the motor shaft in the other one of said bracket members.

5. A food mixer as claimed in claim 4 wherein a floating extensionmember is se'parably connected to the end of the motor shaft and theinner end of one of said drive members is journaled in the aligned endof said motor shaft extension member.

6. A food mixer construction comprising a casing having air holes atopposite ends, a motor stator core positioned in said casingintermediate said air holes, said motor stator core having spacerbrackets and bearing supporting brackets attached to opposite endsthereof, a fan secured on the shaft of said motor adjacent one endthereof, and a brush holder supporting plate secured between the spacerbracket and bearing supporting bracket at one end of said stator core,said plate having a central aperture providing an air passage around themotor commutator whereby air is drawn by said fan through the holes atone end of the casing around the motor windings and through saidapertured plate to

